Robotic manipulator

ABSTRACT

A mechanical manipulator having actuators therein operating across orthogonal pivot joints formed between pivot connection structures and a link arrangement, and also between these same pivot connection structures and a corresponding effector. The actuators are coupled to effectors to position them as selected by having portions of such actuators coupled to the effectors that are capable of moving toward and away from other portions of such actuators connected to the link structure. The components of the mechanical manipulator, except for portions of the effectors, can be enclosed so as to allow the effectors to move in response to the actuators while excluding foreign matter from the enclosed portion thereof.

This is a continuation of application Ser. No. 08/152,677, filed Nov.15, 1993.

BACKGROUND OF THE INVENTION

The present invention relates to controlled motion mechanical membersused as a mechanical manipulator and, more particularly, to a motioncontrollable mechanical manipulator which is in modular form insofar ashaving its actuation members contained therein.

A strong desire for increased automation in the workplace, a need forremotely operable mechanical manipulators, along with an increasedability to control such mechanical manipulators, has led to substantialefforts in the development of robotics. As a result, substantialadvances have occurred in many aspects of robotics.

One aspect permeating robotics is the controlling of mechanicalmanipulators, the portion of a robot used to change positions ororientations of selected objects. Ultimately, such manipulators aredesired to have capabilities similar to those of a human joint such as ashoulder or wrist, perhaps in support of a hand-like appendage, whichcould provide capabilities similar to that of a human arm or better.

Providing a mechanical manipulator simulating a human joint presents adifficult design problem. Such a joint can be considered to have up to 3degrees of freedom in the motion possibilities available to it. A numberof different kinds of mechanical joints for use as mechanicalmanipulators have been proposed which attempt to exhibit 3 degrees offreedom, and some of these have actually achieved such a capability.Typically, such a joint has a base of some sort to which one side of thejoint is fastened, and extending from which a force impartingarrangement is provided to operate movable members located in thisfastened portion of the joint. Mechanical transmission arrangements thencouple this motion on this fastened side of the joint to the controlledside of the joint to cause that joint portion to correspondingly move.Mechanical transmission arrangements so operating the controlled side ofthe joint have been of many kinds, including gears.

However, such joints thus require a mechanical connection arrangement tocontrol motion of the controlled side of the joint. This isdisadvantageous in several respects especially where more than one suchjoint is used in a train in a structure because a mechanical controlarrangement would have to pass through a first joint before being ableto operate the controlled side of a following second joint. To overcomethis difficulty, electrical motors have been installed in the connectionstructure between two such joints so that the second joint at least canbe controlled by motor driven actuators to provide the selected motionof the controlled side of the joint, thus relieving the need to providea mechanical connection extending through more than one joint. Such anarrangement, while workable, results in having a rigid connectionstructure between the two joints which effectively places someconstraints on the bending radius which can be achieved by the structureconsidered in its entirety. Thus, a joint is desired which does notrequire unduly long interconnection portions to be connected thereto tohouse locally provided actuators therefor, particularly interconnectionportions between successive joint member used in a train of such joints.

SUMMARY OF THE INVENTION

The present invention provides a mechanical manipulator having a pair ofmanipulable supports on different sides thereof. A link arrangement isconnected to each of these supports by a corresponding orthogonal pivotconnection structure such that (a) each of the pivot connectionstructures is rotatably connected to the link arrangement so as to berotatable about a corresponding axis established by its rotatableconnections, and such that (b) each of these pivot connection structuresis also rotatably connected to the corresponding one of the manipulablesupports so that each support is rotatable about a corresponding axisestablished by its rotatable connections. The rotatable connection axisinvolving the manipulable support for each such pivot connectionstructure is orthogonal to the axis involved in the rotatable connectionbetween that structure and the link arrangement. Linear actuators arecoupled to the link arrangement and to a corresponding one of themanipulable supports, these actuators having the portions thereof socoupled to the link and to a corresponding support being capable ofselectively approaching or separating from one another.

The actuators can be linear actuators or, alternatively, a motor drivendifferential screw. The coupling between the supports and the linearactuators can be formed by a shell that can be moved with respect to anenclosure that is provided about the link arrangement that otherwiseexposes the manipulable supports. An interior passageway can bemaintained between and through the supports to permit cabling, hoses,and the like to extend through the manipulator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a mechanical manipulator embodying the present invention;

FIGS. 2 and 3 show cross-section views of a portion of the apparatus ofFIG. 1;

FIG. 4 shows another cross-section view of the apparatus of FIGS. 2 and3;

FIG. 5 shows a partially cut-away view of the apparatus of FIGS. 2, 3and 4;

FIG. 6 shows another cross-section view of the apparatus of FIGS. 2, 3and 4;

FIG. 7 shows a cross-section view of an alternative for that portion ofthe apparatus of FIG. 1;

FIG. 8 shows a fragmentary view of an alternative of a portion of theapparatus of FIG. 7;

FIG. 9 shows a cutaway pictorial view of a portion of the apparatus ofFIG. 8;

FIG. 10 shows a cross-section view of an alternative for that portion ofthe apparatus of FIG. 1;

FIG. 11 shows a pictorial view of a portion of the apparatus of FIG. 10;

FIG. 12 shows a cross-section view of a portion of the apparatus of FIG.10; and

FIG. 13 shows a cross-section view of a portion of the apparatus of FIG.10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a mechanical manipulation system, 10, which bears somesimilarities to a human arm but which can be operated more flexibly thana human arm, even appearing as serpentine-like. Mechanical manipulationsystem 10 is shown in an extended, unbent position in FIG. 1 extendingleft to right from a base, 11, supported on some structure, 12, andhaving therein three mechanical manipulators, or joints, 13, 14, and 15,the choice of three being arbitrary as more or fewer joints could beincluded in the system. System 10 further has manipulable supports oreffectors, 16, 17, 18, and 19, extending from the opposite ends ofcorresponding ones of joints 13, 14 and 15, support 16 extending to base11, supports 17 and 18 extending between corresponding pairs of thesejoints, and support 19 extending to form a mount for an arbitrarilychosen end tool. Support, or effector, 16 extending from joint 13 tobase 11, and tool mount support, or effector, 19 are each involved withthe operation of just a single joint, joints 13 and 15, respectively.Supports, or effectors, 17 and 18, however, as indicated above, connectpairs of joints, support 17 connecting joints 13 and 14 and support 18connecting joints 14 and 15.

Mechanical manipulation system 10 is also shown in an alternative bentor "coiled" position in FIG. 1, and in this position the numericaldesignations for the components remain the same as they were in theunbent position, except that those which have changed position inenabling system 10 to reach the bent position have a prime symbol addedthereto. The bent position taken by system 10 is one resulting fromcausing each support, or effector, to reach the greatest angulardifference between it and the axis of the joint, or joints, to which itis connected in an arbitrary plane, a plane which could be considered tobe either a vertically oriented plane or a horizontally oriented planein FIG. 1 depending whether the view is taken as an elevation view or aplan view.

As can be seen, keeping the lengths of the supports 17 and 18, or 17'and 18', as short as possible, and doing the same for the jointsinvolved, allows the smallest possible bending radius for mechanicalmanipulation system 10 in the "coiled" position. Thus, there is asignificant advantage to keeping the motion generating means, oractuators, for joints 13 through 15 located elsewhere than in, or on,supports 16 through 18, i.e. placing them in the interior of joints 13through 15 if they are not lengthened too greatly thereby. Thus,locating them there, the motion generating means, or actuators, fororientating the manipulable supports of a joint with respect to the axisof the joint, should also be kept as compact as possible to aid inkeeping the joint relatively small to thereby achieve a sharper bendingradius for the coiled mechanical manipulation system. The crosshatchedarea in FIG. 1 shows the range of motion possible in the chosen plane ofmechanical manipulation system 10.

FIG. 2 shows a longitudinal cross section view representative of each ofjoints 13, 14 and 15 (although they all do not necessarily have to beexactly the same type or size joint in system 10) with joint ormechanical manipulator 14 being chosen as the actual example. A portionof first designated manipulable support 17, shown as a portion of atube, extends downward in FIG. 2, and outward from joint 14, thisinitial support portion being designated 17" in that figure. Similarly,a portion of complementary manipulable support 18, also shown as aportion of a tube, extends upward in FIG. 2, and again outward fromjoint 14, this complementary support portion being designated 18" inthat figure.

Support portion 17" and support portion 18" are linked to one another bya central link structure, 20, as a base for each and a pair oforthogonal pivot structures, or connectors 21 and 22, all typicallyformed of stainless steel. Central link structure 20 is shown as anelongated tube having a pair of openings, 23 and 24, in the wall thereofto permit passing of control interconnection means therethrough, andfurther having pairs of wall extensions, 25 and 26, at opposite endsthereof. Each extension pair at a corresponding end of central linkstructure 20 has each of its members formed from a corresponding portionof the tubular wall of that structure, each such portion extending pastwhat is otherwise the end of most of that tubular wall to thereby faceone another across the open tubular passageway therebetween, there as aresult being a valley in the tube wall on either side of each extensionof the pair separating each member from the opposite member of thatpair. Each member of extension pair 25 is rotatably connected toorthogonal pivot structure 21 positioned therebetween so that structure21 can rotate with respect to central link structure 20, with one sideor the other of structure 21, between the sides thereof connected toextension pair 25, being in one of the valley openings betweenextensions 25 when that pivot structure is pivoted about the rotatableconnection between it and extension 25. A duplicate of that arrangementis used to rotatably connect orthogonal pivot structure 22 to each ofthe pair of central link structure extension members 26 with structure22 similarly being positioned between extensions 26.

Orthogonal pivot structures 21 and 22 are each formed in a closed loopstructure in having a closed wall around an interior passageway, thatis, each such structure appears much like a truncated tube of a selectedcross section. Although various cross section designs could be used forthese structures, the walls of orthogonal pivot structures 21 and 22have been chosen to be rectangular, or square. Thus, two opposite andparallel sides of orthogonal pivot structure 21 are the sides thereofrotatably connected to central link structure extensions 25 as describedabove and, similarly as describe above, two opposite and parallel sidesof orthogonal pivot structure 22 are the sides thereof rotatablyconnected to central link structure extensions 26.

Orthogonal pivot structure 21, as a result, has two further parallel andopposite sides therein, these being connected in a rotatable connectionto a pair of wall extensions, 27, of support portion 17" with each ofthe members of this pair again formed from a corresponding portion ofthe tubular wall of that structure by having each such portion extendpast what is otherwise the end of most of that tubular wall to therebyface one another across the open tubular passageway therebetween. As aresult, there is a valley in the tube wall on either side of eachextension member of the pair separating each member from the oppositemember of that pair, and which can accommodate rotation of supportportion 17" through allowing sides of pivot structure 21 to intrudetherein during such rotation. As a result, considering this connectingof support portion 17" to central link structure 20 initial supportportion 17" and initial orthogonal pivot structure 21 can pivot togetherwith respect to the axis of tubular central link structure 20 in theelongated direction thereof, and support portion 17" can further pivotwith respect to orthogonal pivot structure 21 and the axis of linkstructure 20.

In the same way, the two remaining opposite and parallel sides of pivotstructure 22 are rotatably connected to a pair of wall extensions, 28,of support portion 18". Thus, considering the connecting of supportportion 18" and central link structure 20, complement support portion18" and complement orthogonal pivot structure 22 can together pivot withrespect to the axis of link structure 20, and support structure 18" canfurther pivot with respect to orthogonal pivot structure 22 and the axisof link structure 20.

Such pivoting possibilities for manipulable support portions 17" and 18"allow the ends thereof to be positioned anywhere on a correspondingspherical surface portion which is limited in extent by the length ofthese support portions, and by each of them encountering obstacles topivoting further at sufficiently large angles between the axis of eachin the elongated direction thereof and the axis of link structure 20.These obstacles form the limits on the edges of the correspondingspherical surface portion, and are imposed by the presence of an outertubular joint enclosure, 29, attached by brackets, 30, to link structure20. Brackets 30 are fastened at one end thereof by screws to enclosure29 with the other ends of these brackets being welded to link structure20. Such moving of either support portion 17" or 18" to a desiredposition on its corresponding spherical surface portion is generated andcontrolled by a corresponding pair of linear actuators, these linearactuators being coupled at one end thereof to central link structure 20by a rotatable connection arrangement, and coupled at the other end tothe corresponding one of support portions 17" and 18".

Thus, in FIG. 2, one of each of the pair of linear actuators associatedwith support portions 17" and 18" is shown with the other of each ofthese pairs either (a) omitted because of the section removed in FIG. 2to provide the cross section view, or (b) unseen because of beingobscured by central link structure 20. Support portion 17" has oneinitial linear actuator, 31, coupled to it. Similarly, support portion18" has one complement linear actuator, 32, coupled to it. Linearactuator 31 is coupled to support portion 17" through being rotatablyconnected to a movable spherical shell portion arrangement, 33, having ahole therein through which support portion 17" protrudes. Similarly,linear actuator 32 is coupled to support portion 18" by being rotatablyconnected to a further movable spherical shell portion arrangement, 34,which in turn has an opening therein through which support portion 18"protrudes. Thus, when either of movable spherical shell portionarrangements 33 or 34 are forced to move by corresponding ones of linearactuators 31 and 32, respectively, the support portion protrudingtherethrough is forced to also move by pivoting as described above inresponse to forces from the edges of the corresponding movable sphericalshell portion arrangement forming the hole through which it protrudes.

Movable spherical shell portion arrangement 33 is formed by twostainless steel spherical shell portions, an inner spherical shellportion, 33', to which linear actuator 31 is directly connected by amount and pivot pin arrangement, 31', and an outer spherical shellportion, 33". These shell portions are positioned concentrically withrespect to, and in contact with, one another such that each can slideover the other within limits which is aided by providing on the slidingsurfaces through high pressure spraying a thin (0.5 μm) tungstendisulfide film sold under the mark DICRONITE® by Lubrication Sciences,Inc. Each of spherical shell portions 33' and 33" is truncated just pastthe equator of the spherical surface about which it is formed, and eachhas an interior hole therethrough but with outer shell portion 33"having a much larger one than does inner shell portion 33'. Inner shellportion 33' instead has the edges of its hole snugly fitted aboutsupport portion 17" protruding therethrough to permit coupling forcesthereto without initial large impacts, and these edges are shown heldthere by a weld, 35, made to support portion 17" for situations wheresealing the interior of joint 14 from the external atmosphere isimportant. A pair of spaced apart snap rings could instead be used tocapture these edges in the space therebetween in situations wheresealing the interior of joint 14 from the external atmosphere is not asimportant as keeping costs as low as possible.

Movable spherical shell portion arrangement 34 is formed in a likemanner by two similar concentric stainless steel spherical shellportions also in contact with one another at thin-film protectedsurfaces such that each can slide on the other, an inner spherical shellportion, 34' to which linear actuator 32 is directly connected by amount and pivot pin arrangement, 32', and an outer spherical shellportion, 34", which are substantially duplicates of inner and outerspherical shell portions 33' and 33", respectively. Also substantiallyduplicated here is the arrangement for coupling movable spherical shellportion arrangement 33 with stainless steel support portion 17" incoupling movable spherical shell portion arrangement 34 with stainlesssteel support portion 18", again shown using a weld, 36, between innerspherical shell portion 34' and support portion 18" to obtain a goodseal. Alternatively, a pair of spaced apart snap rings would again beused if a cheaper construction is desired.

The truncation edge and the interior hole edge of outer spherical shellportion 33" each have an outwardly directed lip formed thereat, 37 and37', as does outer spherical shell portion 34" with similarly locatedlips, 38 and 38'. Lips 37 and 37' can each engage an opposite one of apair of stop surfaces of a seal, 39, typically formed of a fluorocarbonpolymer material sold under the mark TEFLON® by E. I. DuPont de Nemours& Co, which is provided on the interior surface of enclosure 29 at theedge thereof between these lips and between that enclosure and outerspherical shell portion 33". Outer spherical shell portion 33" can beslid along the sliding face surface of seal 39 that it is against, asurface located between and intersecting its two stop surfaces, but onlyso far as is permitted by either one of lips 37 and 37' engaging acorresponding one of these stop surfaces. Seal 39 supported by enclosure29, and with lip 37 pressed thereagainst, together form the obstacleindicated above to limit the angular excursion of support portion 17"from the axis of link structure 20. Support portion 17" is shown at oneangular excursion limit imposed by this limiting arrangement in thelongitudinal cross section view of FIG. 3, and at another in thelongitudinal cross section view of FIG. 4 in which the cross sectionview is taken at a right angle with respect to the cross section view inFIG. 3 to reveal the two remaining linear actuators used, 41 and 42,with initial actuator 41 being directly connected to inner sphericalportion 33' by a mount and pivot pin arrangement, 41', and withcomplement actuator 42 being directly connected to inner sphericalportion 34' by a mount and pivot pin arrangement, 42'. As was done withlinear actuators 31 and 32, actuators 41 and 42 have the opposite endsthereof rotatably connected to central link structure 20.

Similarly, lips 38 and 38' can each engage an opposite one of a pair ofstop surfaces of a seal, 40, formed of the same material and providedbetween enclosure 29 and outer spherical shell portion 34". Here too,seal 40 is provided on the interior surface of enclosure 29 at the edgethereof between these lips. Outer spherical shell portion 34" can beslid along the sliding face surface of seal 40 that it is against, alsoa surface located between and intersecting its two stop surfaces, butonly so far as is permitted by either one of lips 38 and 38' engaging acorresponding one of these stop surfaces. Seal 40 supported by enclosure29, and with lip 38 pressed thereagainst, together form the obstacleindicated above to limit the angular excursion of support portion 18"from the axis of link structure 20. As was shown for support portion17", support portion 18" is shown at one angular excursion limit imposedby this limiting arrangement in FIG. 3, and at another in FIG. 4. Afurther view of this FIG. 3 position of support portion 18" (and to anextent of support portion 17") is provided in the perspective view ofFIG. 5.

As can also be seen in FIGS. 2, 3 and 4, not only do movable sphericalshell portion arrangements 33 and 34 provide the coupling to forcemovements of the corresponding support portions protruding therethroughin response to actuation of the corresponding linear actuators, theyalso complete enclosing the interior space of joint 14 not enclosed byouter tubular enclosure 29. Hence, the interior of joint 14 can be keptrelatively free of outside contaminants by the total enclosure formed byouter tubular enclosure 29 and movable spherical shell portionarrangements 33 and 34. This result can be further improved byextending, for instance, a pneumatic hose through the interior of one ofthe support portions to provide a pressurized atmosphere within joint 14if even greater contamination avoidance is desired. FIG. 4 shows indashed line form a hose passing through the open tubular passageways ofthe support portions, orthogonal pivot structures, and the linkstructure to carry a liquid past joint 14 to a using location, forinstance, paint if joint 14 was used in a spray finishing robot. Such ahose could instead end, or be tapped, in joint 14 and supplied with airunder pressure to pressurize its interior volume. Note that truncatedversions of electrical control cables, 43 and 44, for operating linearactuators 41 and 42, respectively, are shown also in FIG. 4 to extendthrough further openings, 23' and 24', in the wall of the tube structureforming central link structure 20 into the tubular passageway thereinand further into some (or all if desired) of the tubular passagewaysthrough which this hose can extend in joint 14.

As indicated above, the ends of linear actuators 31, 32, 41 and 42 notconnected to one of movable spherical shell portion arrangements 33 and34 are rotatably connected to central link structure 20. Thus, linearactuator 31 has an end thereof rotatably connected to central linkstructure 20 with a bracket and pivot pin arrangement, 31", withactuator 32 being similarly connected using a bracket and pivot pinarrangement, 32", as shown in FIG. 3. Similarly, linear actuator 41 hasan end thereof rotatably connected to central link structure 20 with abracket and pivot pin arrangement, 41", with actuator 42 being similarlyconnected using a bracket and pivot pin arrangement, 42", as shown inFIG. 4. FIG. 6 shows a transverse section view of joint 14 lookinginwardly from a point just above bracket and pivot pin arrangements 31"and 41" rotatably connecting linear actuators 31 and 41 to central linkstructure 20. In this view, all four linear actuators 31, 32, 41 and 42can be seen. Each of bracket and pivot pin arrangements 31", 32", 41"and 42" is capable of permitting the corresponding linear actuatorconnected thereby to central link structure 20 to not only rotate awayfrom and toward the axis of that link structure on the pins holding theactuator, but also from left to right on the pin holding that bracketand pivot pin arrangement to this link structure.

Keeping the volume of joint 14 relatively small requires the use oflinear actuators that are in turn suitably small but with sufficientcapability to force movable spherical shell portion arrangements 33 and34 to selectively move corresponding support portions 17" and 18" tovarious positions as desired. A suitable linear actuator for such use isdescribed in U.S. Pat. No. 5,117,700 to Trechsel which is herebyincorporated herein by reference.

As an alternative to use of such electrically operated linear actuators,pneumatically or hydraulically operated actuators could instead be usedin place thereof. Two such actuator replacements, 45 and 46, are shownin FIG. 7, with the hoses carrying the appropriate fluids for operatingthem shown passing through openings in the wall of the tube structureforming central link structure 20 to thereafter also pass through someor all of the tubular passageways of joint 14. Actuator 45 has its rammounted to inner spherical shell portion 33' by a mount and pivot pinarrangement, 45', and its cylinder coupled to central link structure 20by a bracket and pivot pin arrangement, 45". Actuator 46 has its rammounted to inner spherical shell portion 34' by a mount and pivot pinarrangement, 46', and its cylinder coupled to central link structure 20by a bracket and pivot pin arrangement, 46". Of course, two further suchactuator replacements are also used but are not seen in FIG. 7. Exceptfor these actuator substitutions, the joint of FIG. 7 operates in thesame manner as the joint of FIGS. 2, 3, 4, 5 and 6.

Rather than using fluid carrying hoses to control such pneumatic orhydraulic actuators, the structure walls of the tubular components usedin connecting structure between support portion 17" and 18" in the jointof FIG. 7 can instead have fluid passageways formed entirely thereinwhich, for any one such component, are coupled at the various rotaryjoints of which it is a part to the passageways of next component inthis connection arrangement. Such an arrangement is shown in part inFIG. 8 where central link structure 20, there redesignated 20' in viewof the structural change therein, is shown in part carrying eight smallpassageways, 47, 48, 49, 50, 51, 52, 53 and 54, enclosed in the walls ofthe tubular structure thereof except at the passageway ends with foureach going to a corresponding member of wall extension pair 26,redesignated in FIG. 8 as 26'. Each of these passageways is, asindicated, contained entirely within the wall of the tube structureforming central link 20' leaving sufficient wall thicknesses therearoundto contain the working fluid against the expected fluid pressures exceptat the ends thereof. At these ends such passageways are connected toother components through the rotary connections between connectionarrangement members, or a controlled source of the fluid medium chosenfor operating the actuators.

In FIG. 8, the ends of these passageways 47 through 54 are shown justwhere they connect to the next component in the connection arrangementjoining support portions 17" and 18" which is orthogonal pivot structure22, there redesignated 22'. Pivot structure 22' also has two sets offour small passageways entirely contained within the wall of the squaretubular structure thereof, the first set of four of these passageways,47', 48', 49' and 50', extending from the vicinity of one member of wallextension pair 26' of central link 20 to the vicinity of a member ofwall extension pair 28, redesignated in FIG. 8 as 28', as part ofsupport means 18". This latter wall extension member in turn has thereina corresponding set of four small passageways, 47", 48", 49" and 50". Ina similar manner, pivot structure 22' has therein a second set of smallpassageways 51', 52', 53' and 54', extending from the vicinity of theother wall extension member 26' of central link structure 20' to thevicinity of the other wall extension member 28' of support 18". Thislatter wall extension member also in turn has therein a correspondingset of four small passageways, 51", 52", 53" and 54".

Each of these two sets of passageways in the wall of orthogonal pivotstructure 22' are joined, at the opposite ends of the four membersthereof where they emerge from that wall, to the passageways in thecorresponding one of wall extension members 26' and wall extensionmembers 28' by rotary joints as stated above. These rotary joints,however, permit passage of fluids therethrough between any of thepassageways in any of the wall extension members and the correspondingpassageway in pivot structure 22'. Thus, passageways 47 through 50 inone of the wall extension members 26' of central link structure 20' areeach joined with a corresponding one of passageways 47' through 50' inpivot structure 22' by a multiple fluid passageway joint, 55, whichprovides a rotatable connection between two sides thereof but stillmaintains fluid flow correspondence from passageway inlet to passagewayoutlet for each passageway. These same passageways in pivot structure22' are each joined to a corresponding one of passageways 47" through50" in one of the wall extension members 28' of support portion 18" by afurther correspondence maintaining multiple fluid passageway, rotatableconnection, joint, 56. Similarly, passageways 51 through 54 in theremaining wall extension 26' of central link structure 20' are eachjoined with a corresponding one of passageways 51' through 54' in pivotstructure 22' by another correspondence maintaining multiple fluidpassageway, rotatable connection, joint, 57, with these same passagewaysin pivot structure 22' each being joined with a corresponding one ofpassageways 51" through 54" in remaining wall extension member 28' ofsupport portion 18" by a final correspondence maintaining multiple fluidpassageway, rotatable connection, joint, 58.

An example of one of these correspondence maintaining multiple fluidpassageway, rotatable connection, joints is given in the cutawaypictorial view of FIG. 9, the example being for joint 56. As can beseen, joint 56 has an inner rotation member, 59, and an outer casingmember, 60, with respect to which rotation member 59 can rotate aboutthe axis of elongation common to each. Such rotation of rotation member59 occurs with respect to casing 60 on the surfaces of five polymeric"o"-rings, 61, 62, 63, 64 and 65, positioned therebetween, and aroundinner rotation member 59, these rings being spaced apart from oneanother to expose passageway openings therebetween. Thus, rotationmember 59 is concentrically spaced from casing 60 by "o"-rings 61through 65 with the space between each of these rings serving as acommunication chamber for the corresponding one of the passagewaysprovided in rotation member 59 and the corresponding one of thepassageways provided in casing 60. Thus, the communication chamberformed between "o"-rings 64 and 65 by member 59 and casing 60 serves toconnect a corresponding passageway, 50'", in rotation member 59 with acorresponding passageway, 50"", in casing 60. Inner rotation member 59has three other passageways shown therein, 47'", 48'" and 49'". Thereare a corresponding three further passageways in casing member 60 butwhich cannot be seen in the view of FIG. 9. Hence, even during rotation,fluid under pressure in one of the passageways in rotation member 59will transmit that pressure to fluid in the corresponding one of thepassageways in casing 60. As a result, the pressure of a fluid in one ofthe passageways in rotation member 22' will, through its correspondingpassageways in inner rotation member 59 casing 60, transmit pressure onthe fluid therein to the fluid in the corresponding one of thepassageways in wall extension 28'.

Thus, internal hoses need not be provided through the tubularpassageways in the components connected between support portions 17" and18" to transmit fluid under pressure from the vicinity of central linkstructure 20' to the far opposite end of support portion 18". A similararrangement can be used to provide fluid pressure from the far oppositeend of support portion 17" to the vicinity of central link structure20'. This allows use of pneumatic and hydraulic actuators without thenecessity of filling the tubular passageways of the connectionarrangement between support portion 17" and 18" with hoses to controlthese actuators, the volume of which would reduce the opportunities forother hoses or control cables to pass through these same tubularpassageways to a tool effector at the end of the robot arm such as forpaint spraying.

A further alternative for providing actuators in joint 14 is shown inFIG. 10. Rather than providing four separate actuators, two forpositioning support portion 17" with respect to central link 20 and twofor positioning support portion 18" with respect to the same, the systemof FIG. 10 provides just two screw actuators. One of these actuators,61, can be seen in FIG. 10 but the remaining one is obscured by centrallink structure 20. Actuator 61 is a differential screw arrangement whichhas an outer member rotatable by an electric motor, 62, through drivetrain formed by a flexible elastic drive belt, 63, and a pair ofpulleys, 64, of which one is on motor 62 and the other on the outermember of actuator 61 positioned there in a restraining bracket, 64',which limits movement of that pulley parallel to the axis of link 20 butnot transverse thereto. When so rotated, actuator 61 will simultaneouslymove both inner spherical shell portions 33' and 34' to therebysimultaneously change the positioning of both support portions 17" and18". Actuator 61 is connected to inner spherical shell portion 33' atthe truncation edge thereof by a mount and pivot pin arrangement, 65,and is connected to the truncation edge of inner spherical shell portion34' by a further mount and pivot pin arrangement, 66. Each of mount andpivot pin arrangements 65 and 66 have a threaded nut therein which isconnected by corresponding pivot pins to the mount which is directly incontact with the corresponding one of inner spherical shell portions 33'and 34'. Mount and pivot pin arrangements 65 and 66 are shown in moredetail in FIG. 11.

As indicated in FIG. 10, an offset transverse section view is providedin FIG. 12. As a result, a second screw actuator, 67, can be seen incross-section which in turn is rotatable by a further electric motor,68, again through use of a flexible elastic belt, 69, and a pair ofpulleys, 70, of which one here too is on motor 68 and the other on theouter member of actuator 67 positioned there in a restraining bracket,70', which limits movement of that pulley parallel to the axis of link20 but not transverse thereto. In FIG. 12, differential screw 61 cansimultaneously move the truncation edges of inner spherical shellportions 33' and 34' where it is attached, causing each such edge tomove inward and outward with respect to the plane of that figure tothereby cause support portions 17" and 18" coupled to these sphericalshell portions, although not shown, to correspondingly move eithertoward the left or the right in the view of that figure. Similarly,screw actuator 67 is formed with a differential screw that can cause thetruncated edges of spherical shell portions 33' and 34', where it isattached, to move inward and outward with respect to the plane of thatfigure to effectively cause corresponding support portions 17" and 18"to move downward and upward in the view of that figure.

FIG. 13 shows a cross-section view of either of differential screws 61or 67 with the corresponding member of one of pulley pairs 64 and 70 asthe outermost radial structure thereof. Such a pulley member is fixedlyattached to an exterior surface of an outer sleeve, 71, which isinteriorly threaded at one diameter over most of its interior surfacebut at a smaller diameter on the two inset interior surfaces provided onthe interior surfaces of the smaller openings in the reduction end capslocated at each end thereof.

Within outer sleeve 71 are two further inner sleeves, 72 and 73, both ofwhich are threaded on most of the outer surfaces thereof at one diameterto engage the threads on the inset interior surfaces of the reductionend caps of outer sleeve 71. In addition, the outer surfaces of theinner sleeves are also threaded at a larger diameter in the portionthereof provided by the outer surfaces of the expansion end cap of eachinterior sleeve provided at the interior end thereof to engage thethreading prevalent over most of the interior surface of outer sleeve71. The interior surfaces of each of interior sleeves 71 and 72 areinteriorly threaded at one diameter over most of the interior surfacethereof but at a smaller diameter on an inset interior surface providedon the interior surface of the smaller opening in the reduction end caplocated at the end thereof (the exterior end) opposite that with theexpansion end cap thereon.

Within each of inner sleeves 72 and 73 are corresponding threaded rods,74 and 75, respectively, each of which has an expansion end cap on eachof its ends. Each of threaded rods 74 and 75 are threaded on most of theouter surfaces thereof at one diameter to engage the threads on theinset interior surface of the reduction end cap of the correspondinginner sleeve in which it is provided. In addition, the outer surface ofeach rod is also threaded at a larger diameter on the portion thereofprovided by the outer surface of the expansion end cap of each rodlocated at the interior end thereof to engage the threading prevalentover most of the interior surface of the inner sleeve in which it isprovided.

Under rotation of the pulley on outer sleeve 71, that sleeve will alsorotate causing either the inner sleeves or the rods therein to alsorotate, depending on which as the least frictional force hinderingrotation thereof. In one direction of such rotation, the threading issuch that the exterior ends of the rods will recede from outer sleeve71, and such that rotation in the other direction will lead to theseexterior rod ends approaching outer sleeve 71. Sufficient rotation tocause an end cap on one component to reach an end cap of another resultsin the latter end cap becoming a stop and a transferor of torque to thecomponent of which it is a part. Thus, the rods and inner sleeves"telescope" into and out of outer sleeve 71 under rotation of thatlatter sleeve to have a relatively short extent if support portions 17"and 18" are pulled over them, as caused by such a short extensionthereof in having the exterior rod ends connected to the correspondingone of inner spherical shell portions 33' and 34' through mount andpivot pin arrangements 65 and 66, respectively, and a relatively longextent if support portions 17" and 18" are pushed by them away fromthem.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. Robotic apparatus including first roboticmanipulator having an initial manipulable support and a complementmanipulable support on different sides thereof, said first manipulatorcomprising:a link structure; an initial pivot connector rotatablyconnected to said link structure about a first axis and furtherrotatably connected to said initial manipulable support about a secondaxis oriented angularly to said first axis; a complement pivot connectorrotatably connected to said link structure about a third axis, andfurther rotatably connected to said complement manipulable support abouta fourth axis oriented angularly to said third axis; and first initialand first complement actuators each having a pair of body portionstherein which can selectively be caused to approach and separate fromone another, said first initial actuator having one of said pair of bodyportions thereof coupled to said link structure and having that saidbody portion thereof remaining coupled to said initial manipulablesupport independently of said initial and complement pivot connectors,said first complement actuator having one of said pair of body portionsthereof coupled to said link structure and having that said body portionthereof remaining coupled to said complement manipulable supportindependently of said initial and complement pivot connectors.
 2. Theapparatus of claim 1 wherein said link structure has an enclosurethereabout having a complement opening therein to permit said complementmanipulable support to emerge therefrom, said first complement actuatorbeing coupled to said complement manipulable support by a complementshell movable with respect to said enclosure and with said complementshell having an opening therein to permit said complement manipulablesupport to emerge therefrom but otherwise substantially covering saidenclosure complement opening.
 3. The apparatus of claim 1 wherein saidfirst and second axes of said initial pivot connector are substantiallyorthogonal to one another and said third and fourth axes of saidcomplement pivot connector are substantially orthogonal to one another,and wherein those two locations at which said coupling of said firstinitial actuator means to said link structure and said coupling of saidfirst complement actuator to said link structure, along with that pivotconnector direction established between said rotatable connections ofsaid initial and complement pivot connectors to said link structure,define a first link-actuator plane; and further comprising secondinitial and second complement actuators each having a pair of bodyportions therein which can selectively be caused to approach andseparate from one another, said second initial actuator having one ofsaid pair of body portions thereof coupled to said link structure andthat said body portion thereof remaining coupled to said initialmanipulable support, and said second complement actuator having one ofsaid pair of body portions thereof coupled to said link structure andthat said body portion thereof remaining coupled to said complementmanipulable support, such that said coupling of said second initialactuator to said link structure and said coupling of said secondcomplement actuator to said link structure, along with said pivotconnection direction, establish a second link-actuator plane which issubstantially orthogonal to said first link-actuator plane.
 4. Theapparatus of claim 1 wherein those said body portions of said firstinitial and first complement actuators coupled to said link structuretogether form a common differential screw threaded shell which iscoupled to said link structure at a location at which is provided arotary motion generation means which can selectively rotate a selectedmember of a rotary motion drive train means, said coupling between saidcommon differential screw threaded shell and said rotary motiongeneration means being provided by said rotary motion drive train means.5. The apparatus of claim 1 wherein said initial and complementmanipulable supports, said initial and complement pivot connectors andsaid link structure each have an interior passageway therethrough suchthan an elongated flexible structure can extend commonly through all ofthem.
 6. The apparatus of claim 1 wherein said link structure is atleast in part a tube-like structure formed by a tubular wall about aninterior passageway with that said tubular wall having at least onetubular passageway therein which opens to neither said interiorpassageway thereof nor to exterior regions immediately outside said linkstructure tubular wall opposite that said interior passageway; andwherein said complement manipulable support is at least in part atube-like structure formed by a tubular wall about an interiorpassageway with that said tubular wall having at least one tubularpassageway therein which opens to neither said interior passagewaythereof nor to exterior regions outside said complement manipulablesupport tubular wall opposite that said interior passageway; and whereinsaid complement pivot connector is at least in part a tube-likestructure formed by a tubular wall about an interior passageway withthat said tubular wall having at least one tubular passageway thereinwhich opens to neither said interior passageway thereof nor to exteriorregions outside said complement pivot connector tubular wall oppositethat said interior passageway; and further wherein said link structuremeans and said complement pivot connector are rotatably connected asaforesaid by a rotatable connection which permits said link structuretubular passageway to maintain communication with said complementpivotal connector tubular passageway, and said complement pivotconnector and said complement manipulable support are rotatablyconnected as aforesaid by a rotatable connection which permits saidcomplement pivot connector tubular passageway to maintain communicationwith said complement manipulable support tubular passageway.
 7. Theapparatus of claim 1 wherein said first initial and first complementactuators are each a linear actuator.
 8. The apparatus of claim 1further comprising a second robotic manipulator having an initialmanipulable support joined with said first robotic manipulatorcomplement manipulable support without having motors in or on thesejoined supports for operating either of said first and second roboticmanipulators.
 9. The apparatus of claim 2 wherein said complement shellis formed by both an inner complement shell and an outer complementshell positioned against one another with said outer complement shellbeing slidable over said inner complement shell, said inner and outercomplement shells each having a hole therein to permit said complementmanipulable support to emerge therefrom as aforesaid but with said outercomplement shell having a hole of a substantially greater size than thatin said inner complement shell, said first complement actuator beingrotatably connected to said inner complement shell means.
 10. Theapparatus of claim 2 wherein said enclosure also has an initial openingtherein to permit said initial manipulable support to emerge therefrom,said first initial actuator being coupled to said initial manipulablesupport by an initial shell movable with respect to said enclosure andwith said initial shell having an opening therein to permit said initialmanipulable support to emerge therefrom but otherwise substantiallycovering said enclosure initial opening.
 11. The apparatus of claim 3wherein said first and second initial actuator and said first and secondcomplement actuators are each a linear actuator.
 12. The apparatus ofclaim 4 wherein said body portion of said first initial actuator coupledto said initial manipulable support is coupled thereto at least in partby a rotatably mounted threaded nut, and wherein said body portion ofsaid first complement actuator coupled to said complement manipulablesupport is coupled thereto at least in part by a rotatably mountedthreaded nut.
 13. The apparatus of claim 5 wherein said interiorpassageways can also accommodate control interconnections therethroughfor said first initial and said first complement actuators.
 14. Theapparatus of claim 8 wherein said second robotic manipulator has saidinitial manipulable support and a complement manipulable support ondifferent sides thereof, said second manipulator comprising:a linkstructure; an initial pivot connector rotatably connected to said linkstructure about a first axis and further rotatably connected to saidinitial manipulable support about a second axis oriented angularly tosaid first axis; a complement pivot connector rotatably connected tosaid link structure about a third axis, and further rotatably connectedto said complement manipulable support about a fourth axis orientedangularly to said third axis; and first initial and first complementactuators each having a pair of body portions therein which canselectively be caused to approach and separate from one another, saidfirst initial actuator having one of said pair of body portions thereofcoupled to said link structure and having that said body portion thereofremaining coupled to said initial manipulable support, said firstcomplement actuator having one of said pair of body portions thereofcoupled to said link structure and having that said body portion thereofremaining coupled to said complement manipulable support.
 15. Theapparatus of claim 9 wherein said outer complement shell is retainedwithin said enclosure at said enclosure complement opening by acomplement seal positioned around an interior edge of said enclosurecomplement opening, said outer complement shell having lips protrudingoutwardly both at an edge of said hole therein that permits saidcomplement manipulable support to emerge therefrom and at an edge ofanother opening across therefrom in said outer complement shell.
 16. Theapparatus of claim 10 wherein said initial shell is formed by both aninner initial shell and an outer initial shell positioned against oneanother with said outer initial shell being slidable over said innerinitial shell, said inner and outer initial shell each having a holetherein to permit said initial manipulable support to emerge therefromas aforesaid but with said outer initial shell having a hole of asubstantially greater size than that in said inner initial shell, saidfirst complement actuator being rotatably connected to said innerinitial shell.
 17. The apparatus of claim 14 wherein said secondmanipulator link structure has a second manipulator enclosure thereabouthaving a complement opening therein to permit said second manipulatorcomplement manipulable support to emerge therefrom, said secondmanipulator first complement actuator being coupled to said secondmanipulator complement manipulable support by a second manipulatorcomplement shell movable with respect to said second manipulatorenclosure and with said second manipulator complement shell having anopening therein to permit said second manipulator complement manipulablesupport to emerge therefrom but otherwise substantially covering saidsecond manipulator enclosure complement opening.
 18. The apparatus ofclaim 14 wherein those two locations at which said coupling of saidsecond manipulator first initial actuator to said second manipulatorlink structure and said coupling of said second manipulator firstcomplement actuator to said manipulator link structure, along with thatpivot connector direction established between said rotatable connectionsof said second manipulator initial and complement orthogonal pivotconnectors to said second manipulator link structure, define a firstlink-actuator plane, and further comprising second manipulator secondinitial and second complement actuators each having a pair of bodyportions therein which can selectively be caused to approach andseparate from one another, said second manipulator second initialactuator having one of said pair of body portions thereof coupled tosaid second manipulator link structure and that said body portionthereof remaining coupled to said second manipulator initial manipulablesupport, and said second manipulator second complement actuator havingone of said pair of body portions thereof coupled to said secondmanipulator link structure and that said body portion thereof remainingcoupled to said second manipulator complement manipulable support, suchthat said coupling of said second manipulator second initial actuator tosaid second manipulator link structure and said coupling of said secondmanipulator second complement actuator to said second manipulator linkstructure, along with said pivot connection direction, establish asecond link-actuator which is substantially orthogonal to said firstlink-actuator plane.
 19. The apparatus of claim 14 wherein those said,body portions of said second manipulator first initial and firstcomplement actuators coupled to said second manipulator link structuretogether form a common second manipulator differential screw threadedshell which is coupled to said second manipulator link structure at alocation at which is provided a second manipulator rotary motiongeneration means which can selectively rotate a selected member of asecond manipulator rotary motion drive train means, said couplingbetween said common second manipulator differential screw threaded shelland said second manipulator rotary motion generation means beingprovided by said second manipulator rotary motion drive train means. 20.The apparatus of claim 14 wherein said second manipulator initial andcomplement manipulable supports, said second manipulator initial andcomplement pivot connectors, and said second manipulator link structureeach have an interior passageway therethrough such that an elongatedflexible structure can extend commonly through all of them.
 21. Theapparatus of claim 16 wherein said outer initial shell is retainedwithin said enclosure at said enclosure initial opening by an initialseal positioned around an interior edge of said enclosure initialopening, said outer initial shell having lips protruding outwardly bothat an edge of said hole therein that permits said initial manipulablesupport to emerge therefrom and at an edge of another opening acrosstherefrom in said outer initial shell.
 22. A first robotic manipulatorhaving an initial manipulable support, said first manipulatorcomprising:a base structure; an initial pivot connector rotatablyconnected to said base structure about a first axis and furtherrotatably connected to said initial manipulable support about a secondaxis oriented angularly to said first axis; and first and second initialactuators each having a pair of body portions therein which canselectively be caused to approach and separate from one another, saidfirst and second initial actuators each having one of said pair of bodyportions thereof coupled to said base structure and each having thatsaid body portion thereof remaining coupled to said initial manipulablesupport independently of said initial pivot connector so as to have eachof said first and second initial actuators be able to move said initialmanipulable support in a direction corresponding thereto that issubstantially orthogonal to said corresponding direction of movement ofthat remaining other actuator.
 23. The manipulator of claim 22 whereinsaid base structure has an enclosure thereabout having an initialopening therein to permit said initial manipulable support to emergetherefrom, said first and second initial actuators being coupled to saidinitial manipulable support by an initial shell movable with respect tosaid enclosure and with said initial shell having an opening therein topermit said initial manipulable support to emerge therefrom butotherwise substantially covering said enclosure initial opening.
 24. Themanipulator of claim 22 wherein said initial manipulable support, saidinitial orthogonal pivot connector, and said base structure each have aninterior passageway therethrough such that an elongated flexiblestructure can extend commonly through all of them.
 25. The manipulatorof claim 23 wherein said initial shell is formed by both an innerinitial shell and an outer initial shell positioned against one anotherwith said outer initial shell being slidable over said inner initialshell, said inner and outer initial shells each having a hole therein topermit said initial manipulable support to emerge therefrom asaforesaid, but with said outer initial shell having a hole of asubstantially greater size than that in said inner initial shell, saidfirst and second initial actuators each being rotatably connected tosaid inner initial shell means.
 26. The manipulator of claim 25 whereinsaid outer initial shell is retained within said enclosure at saidenclosure initial opening by an initial seal positioned around aninterior edge of said enclosure initial opening, said outer initialshell having lips protruding outwardly both at an edge of said holetherein that permits said initial manipulable support to emergetherefrom and at an edge of another opening across therefrom in saidouter initial shell.
 27. Robotic apparatus including first roboticmanipulator having an initial manipulable support and a complementmanipulable support on different sides thereof, said first manipulatorcomprising:a link structure; an initial pivot connector rotatablyconnected to said link structure about a first axis and furtherrotatably connected to said initial manipulable support about a secondaxis oriented angularly to said first axis; a complement pivot connectorrotatably connected to said link structure about a third axis, andfurther rotatably connected to said complement manipulable support abouta fourth axis oriented angularly to said third axis; and first initialand first complement actuators each having a pair of body portionstherein which can selectively be caused to approach and separate fromone another, said first initial actuator having one of said pair of bodyportions thereof coupled to said link structure so as to limittranslation of that said body portion in all directions with respect tosaid link structure and having that said body portion thereof remainingcoupled to said initial manipulable support, said first complementactuator having one of said pair of body portions thereof coupled tosaid link structure so as to limit translation of that said body portionin all directions with respect to said link structure and having thatsaid body portion thereof remaining coupled to said complementmanipulable support.
 28. A first robotic manipulator having an initialmanipulable support, said first manipulator comprising:a base structure;an initial pivot connector rotatably connected to said base structureabout a first axis and further rotatably connected to said initialmanipulable support about a second axis oriented angularly to said firstaxis; and first and second initial actuators each having a pair of bodyportions therein which can selectively be caused to approach andseparate from one another, said first and second initial actuators eachhaving one of said pair of body portions thereof coupled to said basestructure so as to limit translation of that said body portion in alldirections with respect to said base structure and each having that saidbody portion thereof remaining coupled to said initial manipulablesupport so as to have each of said first and second initial actuators beable to move said initial manipulable support in a directioncorresponding thereto that is substantially orthogonal to saidcorresponding direction of movement of that remaining other actuator.